- glBegin(GL_LINES);
- glVertex3i( 0.0, 0.0, lineLength );
- glVertex3i( 0.0, 0.0, -lineLength );
- glEnd();
+ glVertex3i( lineLength, 0.0, 0.0 );
+ glVertex3i( lineLength - arrowLength, 0.0, -1.0 );
+
+ // z arrow
+ glVertex3i( 0.0, 0.0, lineLength );
+ glVertex3i( 0.0, 0.0, -lineLength );
+
+ // z arrowheads
+ glVertex3i( 0.0, 0.0, lineLength );
+ glVertex3i( 1.0, 0.0, lineLength - arrowLength );
+
+ glVertex3i( 0.0, 0.0, lineLength );
+ glVertex3i( -1.0, 0.0, lineLength - arrowLength );
+ glEnd();